class Animal {
    public void makeSound() {
        System.out.println("Animal sound");
    }
}
class Dog extends Animal {
    @Override
    public void makeSound() {
        System.out.println("汪汪汪");
    }
}
class Cat extends Animal {
    @Override
    public void makeSound() {
        System.out.println("喵喵喵");
    }
}
public class work06 {
    public static void main(String[] args) {
        Animal a = new Dog();
        a.makeSound();
    }
}
